Nucleophilic addition and substitution at coordinatively saturated boron by facile 1,2-hydrogen shuttling onto a carbene donor
Please always quote using this URN: urn:nbn:de:bvb:20-opus-170255
- The reaction of [(cAAC\(^{Me}\))BH\(_{3}\)] (cAAC\(^{Me}\) = 1-(2,6-iPr\(_{2}\)C\(_{6}\)H\(_{3}\))-3,3,5,5-tetramethylpyrrolidin-2-ylidene) with a range of organolithium compounds led to the exclusive formation of the corresponding (dihydro)organoborates, Li\(^{+}\)[(cAAC\(^{Me}\)H)BH\(_{2}\)R]− (R = sp\(^{3}\)-, sp\(^{2}\)-, or sp-hybridised organic substituent), by migration of one boron-bound hydrogen atom to the adjacent carbene carbon of the cAAC ligand. A subsequent deprotonation/salt metathesis reaction with Me3SiCl or spontaneous LiHThe reaction of [(cAAC\(^{Me}\))BH\(_{3}\)] (cAAC\(^{Me}\) = 1-(2,6-iPr\(_{2}\)C\(_{6}\)H\(_{3}\))-3,3,5,5-tetramethylpyrrolidin-2-ylidene) with a range of organolithium compounds led to the exclusive formation of the corresponding (dihydro)organoborates, Li\(^{+}\)[(cAAC\(^{Me}\)H)BH\(_{2}\)R]− (R = sp\(^{3}\)-, sp\(^{2}\)-, or sp-hybridised organic substituent), by migration of one boron-bound hydrogen atom to the adjacent carbene carbon of the cAAC ligand. A subsequent deprotonation/salt metathesis reaction with Me3SiCl or spontaneous LiH elimination yielded the neutral cAAC-supported mono(organo)boranes, [(cAAC\(^{Me}\)H)BH\(_{2}\)R]− (R]. Similarly the reaction of [cAAC\(^{Me}\))BH\(_{3}\)] with a neutral donor base L resulted in adduct formation by shuttling one boron-bound hydrogen to the cAAC ligand, to generate [(cAAC\(^{Me}\)H)BH\(_{2}\)L], either irreversibly (L = cAAC\(^{Me}\)) or reversibly (L = pyridine). Variable-temperature NMR data and DFT calculations on [(cAAC\(^{Me}\)H)BH\(_{2}\)(cAAC\(^{Me}\))] show that the hydrogen on the former carbene carbon atom exchanges rapidly with the boron-bound hydrides.…
Author: | Dominic AuerhammerORCiD, Merle ArrowsmithORCiD, Holger BraunschweigORCiD, Rian D. DewhurstORCiD, J. Oscar C. Jiménez-HallaORCiD, Thomas Kupfer |
---|---|
URN: | urn:nbn:de:bvb:20-opus-170255 |
Document Type: | Journal article |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Anorganische Chemie |
Language: | English |
Parent Title (English): | Chemical Science |
Year of Completion: | 2017 |
Volume: | 8 |
Issue: | 10 |
Pagenumber: | 7066–7071 |
Source: | Chemical Science, 2017, 8(10), 7066-7071. DOI: 10.1039/c7sc03193a |
DOI: | https://doi.org/10.1039/c7sc03193a |
Pubmed Id: | https://pubmed.ncbi.nlm.nih.gov/29147534 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 546 Anorganische Chemie |
Tag: | boron-bound hydrogen; carbene donor; nucleophilic addition; nucleophilic substitution |
Release Date: | 2019/09/23 |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung |